Player pianos utilize perforated paper tapes and a playback mechanism to provide recorded music. Of necessity, they are limited to the pre-recorded content. The paper tape is unrolled from a supply reel or spool past a set of fingers which locate the holes in the roll or tape causing the player mechanism to play the recorded melody. The old fashioned player piano invokes much nostalgia but it is limited in several regards. It is difficult for the owner to record his own music, and transmission of recorded signals is almost impossible. The only transmission that is actually available is by physical transfer of recorded paper tape. These limitations have materially constrained the use of player pianos except in a sentimental fashion.
The present invention is to be contrasted in many regards. It provides a device which forms a single channel output signal which can be transmitted over a two wire system using a multi-level modulator system or a bi-level transmission system transferring a minimum number of bits. Communication channels able to handle as low as about 2200 bits per second will suffice. This means that even telephone grade transmission systems are suitable for the apparatus without any degradation of performance. The apparatus defines an encoder and decoder which formats a signal having a minimum number of bits, thereby reducing the degree of sophistication and expense required in the device.